Telescopic jib for a motor vehicle or a crane

ABSTRACT

A telescopic boom ( 1 ) for a vehicle ( 25 ) or a hoist with a storage rack ( 6 ) for at least two box girders ( 2, 3 ) guided displaceably in one another in the direction of their longitudinal axes, which are mounted to pivot about a horizontal pivot axle ( 5 ) in the storage rack ( 6 ) and which can be displaced reciprocally by means of a servo-drive ( 19 ) is described. In order to create advantageous structural conditions it is proposed that the longitudinal axles of the box girders ( 2, 3 ) form an upwards arched arc of a circle ( 4 ) which runs concentrically to a common axis parallel to the pivot axis ( 5 ).

CROSS-REFERENCE TO RELATED APPLICATIONS

Applicants claim priority under 35 U.S.C. §119 of Austrian ApplicationNo. A 878/99 filed May 18, 1999. Applicants, also claim priority under35 U.S.C. §365 of PCT/AT00/00128 filed May 10, 2000. The internationalapplication under PCT article 21(2) was not published in English.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to a telescopic boom for a vehicle or ahoist with a storage rack for at least two box girders guideddisplaceably in one another in the direction of their longitudinal axes,which are mounted to pivot about a horizontal pivot axle in the storagerack and which can be displaced reciprocally by means of a servo-drive.

2. Description of the Prior Art

Known telescopic booms of this type (DE 27 21 636 A1, DE 38 04 557 A1)have box girders guided in one another which can be displacedreciprocally along a straight line by means of a ram. The lower one ofthe box girders can be pivoted in a storage rack about a horizontalpivot axis and be pivoted with the bogie about a vertical axis, so thatthe load suspension arranged at the front end of the telescopic boom canbe moved freely in a spatial area created by the possible pivot or swingangle and the extension length. If in the process the load suspension isarranged on a swivel head pivoting about a vertical axis, then inaddition the load alignment can be selected independently of therespective pivot adjustment of the telescopic boom relative to thevertical axis of the storage rack. The design of the individual sectionsof the telescopic boom as box girders not only offers advantages withrespect to the carrying capacity of the telescopic boom, but also withrespect to arrangement of the servo-drive for extending and retractingthe telescopic boom as well as to the placing of supply lines, becausethe servo-drive and the supply lines can be placed inside the boxgirders. This applies in particular for an embodiment (DE 27 21 636 A1)wherein the upper and the lower wall of the box girder, which is guidedin the box girder on the storage rack side, exhibit longitudinal edgeframes projecting over the box profile and guided on the box girder onthe storage rack side, which with angled edge sections form takeupgrooves for supply lines for hydraulic supply of rams of the loadsuspension. But the disadvantage of these known telescopic booms is thata linear, free passage for the telescopic arm has to be availablebetween the point to be reached by the front end of the telescopic boomand the storage rack, which is, however, often not present, for examplenot if the telescopic boom is to be inserted into a space overheadthrough lateral openings. The higher such a lateral aperture lies abovethe storage rack, the more steeply therefore the telescopic arm has tobe mounted about its horizontal pivot axis, the less the possiblehorizontal penetration width of the telescopic boom through the lateralopening becomes. To avoid this drawback the boom can be provided as abuckling arm with an articulated partitioning, though such buckling armbooms necessitate substantially higher structural and control expenses.

SUMMARY OF THE INVENTION

The object of the invention is to arrange a telescopic boom for avehicle or a hoist of the type described at the outset such that placescan be reached with the telescopic boom, between which and the storagerack there is no free linear passage, without having to fall back on anadditional articulated partitioning of the boom.

The invention solves this task by the fact that the longitudinal axlesof the box girders form an upwards arched arc of a circle which runsconcentrically to a common axis parallel to the pivot axis.

Since, as a result of these measures, the box girders are pushed towardsone another along a curved path, free linear passage for the telescopicboom is no longer required, which considerably expands the area ofapplication of telescopic boom according to the present invention ascompared to conventional telescopic booms. The horizontal components ofthe extension movement by box girders formed in an arc of a circlebecomes overproportionally greater with increasing extension length, inparticular with steeper set angles of the telescopic boom, such thatsuch telescopic booms are particularly suitable for reaching spaceswhich are accessible overhead via a lateral opening.

Because of the arrangement of the box girders concentric to a commonaxis there are no particular difficulties with respect to the reciprocalguiding of the box girders above the cylindrical walls. The box girders,which engage in one another with play, can be mutually supported in theusual way by slideways which are arranged in the vicinity of the frontor rear girder end of the intermeshing box girders, due to the requiredtorque support. To be able to guarantee a greater area of tolerance forthe curving of the box girders, the slideways can be swivel-mounted onthe girder ends about an axle parallel to the pivot axle, so that thereis automatic adaptation to the respective curving of the cylindricalwalls of the box girders in the region of these load-reducing slideways.

Whereas mutual adjustment of the intermeshing box girders produces nodifficulties with use of a cylindrical pinion in the case of straighttelescopic booms, the arrangement of a cylindrical pinion inside the boxgirders in the case of box girders curved to an arc of a circle requiresspecial measures, since by means of a linear extending ram the curvedform of the box girders cannot be considered. For this reason thecylindrical pinion may comprise two rams which are on the one handarticulated to one of the outer girder ends and on the other hand to acommon slider mounted displaceably inside the box girder, such that therams form a progression adapted to the circular arc shape, in such a waythat the rams extend chord-like inside the box girders in linearfashion. The slider mounted displaceably inside the inner box girderbetween both rams enables simple mutual displacement of the box girderswith simultaneous removal of the radial components of the controllingtorque on the box girders. A servo-drive is also proposed for mutualdisplacement of the box girders however, comprising at least one rackrunning along a box girder and one driving pinion of the other boxgirder meshing with the rack, so that the box girder connected to thedriving pinion is driven along the other box girder with the drive ofthe driving pinion.

It is evident that the arc-shaped box girders according to the presentinvention can also be employed to accommodate supply lines, if the upperand the lower cylindrical wall of the inner box girder form, in a mannerknown per se, longitudinal edge frames projecting laterally over the boxprofile and guided on the outer box girder, between which longitudinalchannels for taking up these supply lines are formed on the outer sidesof the box profile of the inner box girder. These supply lines can servevarious purposes, according to the use of the telescopic boom.Accordingly, when telescopic booms according to the present inventionare used for fire engines, guide hoses for extinguishers can be laid inthese longitudinal channels next to the supply lines for the equipmenttaken up by the telescopic boom. If supply lines of a larger diameterare required, as is the case for supplying fresh concrete or mortar forexample, the box profile of the inner box girder can also be employed asa supply line, so that the cross-section of the box girders does nothave to be enlarged. In this case, however, the servo-drive cannot bearranged inside the box profile. For this reason the servo-drive maycomprise a rack-and-pinion gear, such that the rack of the servo-driveis to be provided in at least one of the longitudinal channels resultingbetween the longitudinal edge frames outside the box profiles on bothsides of the inner box girder, so that the box profile is free forsupply.

To further expand the reach of the telescopic boom the box girderforming the overhanging boom end can bear a boom arm pivoting about ahorizontal pivot axis and possibly extending telescopically, whichconsiderably increases the reach of the telescopic boom in cooperationwith the circular arc of the telescopic boom on account of its pivotedconfiguration; this is of particular significance for telescopic boomswhich are used with feed pipes for different goods, e.g. liquids,liquid-solid mixtures or pourable goods.

Telescopic booms for vehicles generally have only two intermeshing boxgirders so as not to rise above preset contours of the vehicle. A simplearrangement of three box girders guided displaceably in one another iscreated with an economic arrangement if the box girder swivel-mounted inthe storage rack is designed shorter than the middle box girdertelescoping upwards and downwards from the box girder on the rack side,because utilisation of the space underneath the rack for lowering themiddle box girder allows arrangement of a three-part telescopic boominside the admissible contours of the vehicle. In this connection itshould be considered that with box girders curved in the form of acircular arc not only the length of the telescopic boom, but also itsgreater horizontal extension determined by the circular form is to betaken into consideration.

As already pointed out, telescopic booms according to the presentinvention can be used in multiple applications. Inter alia it ispossible to utilise the box girders not only for guiding supply lines,but also to design them as accessible and/or navigable tunnel. Thesecorrespondingly large-sized box girders can advantageously facilitateconnecting an aircraft exit hatch to the ground, with the addedadvantage that, despite different exit hatch paths, the connection endof the telescopic boom on the aircraft runs approximately horizontally,before the tunnel floor gradually inclines downwards to overcome theheight. The circumstances by which the telescopic boom can be joined toan opening at a distance above an accessible surface with minimalinclination, makes telescopic booms with box girders forming a tunnelalso suitable for creating emergency and escape routes, particularly asthese emergency and escape routes are protected at least partially fromoutside influences by the box girders enclosing them.

Another area of application of telescopic booms according to the presentinvention is in vehicles which pick up set-down bins. Such vehicles arefitted with telescopic booms which have at their front end a pivot headfor load suspension gear which forms a cross-beam with tractionmechanisms arranged laterally in pairs for hanging the bins. When thetelescopic boom is adjusted along a circular path the advantagesassociated with such a telescopic boom for setting down and picking upbins can be utilised to particular advantage. At the same time at leastone of the traction mechanisms arranged in pairs can be shifted on eachside of the cross-beam relative to the traction mechanism assigned toit, to enable the bins to be tipped and emptied using the differentlever length of the traction mechanisms. Although the drive foradjusting the traction mechanisms can be varying in design, particularlysimple structural ratios result if the adjustable traction mechanismsengage in hydraulic jacks mounted in the cross-beam, so that when thesehydraulic jacks are supplied the bin suspended on the tractionmechanisms can accordingly be tipped, and certainly in any directionwhatsoever, because the pivoted position of the cross-beam can beselected by the pivot head independently of the pivot position of thetelescopic boom about the axis of the storage rack.

BRIEF DESCRIPTION OF THE DRAWING

The inventive object is illustrated by way of example in the diagrams,in which:

FIG. 1 shows a telescopic boom according to the present invention for avehicle or a hoist in side elevation,

FIG. 2 shows this telescopic boom in a plan view,

FIG. 3 shows the telescopic boom in longitudinal section,

FIG. 4 shows the telescopic boom in section according to FIGS. 1 to 3 inthe vicinity of the intermeshing ends of the box girders in longitudinalsection on an enlarged scale, FIG. 5 shows a section according to lineV—V in FIG. 4,

FIG. 6 shows a section according to line VI—VI in FIG. 4,

FIG. 7 shows a structural variant of a telescopic boom according to thepresent invention in section in side elevation on an enlarged scale,

FIG. 8 shows a section according to line VIII—VIII in FIG. 7,

FIG. 9 shows a vehicle fitted with a telescopic boom according to thepresent invention for taking up set-down bins in side elevation,

FIG. 10 shows the vehicle according to FIG. 9 in a rear view with a bintipped on the side of a vehicle,

FIG. 11 shows a plan view of the vehicle in FIGS. 9 and 10 withdifferent set-down positions for a bin on a reduced scale,

FIG. 12 shows a longitudinal section through the cross-beam of the loadsuspension gear of the telescopic boom as in FIGS. 9 to 11 on anenlarged scale,

FIG. 13 shows a telescopic boom placed on a vehicle for guiding a supplyline for ready-made concrete,

FIG. 14 shows the vehicle as in FIG. 13 in a plan view,

FIG. 15 shows the vehicle as in FIGS. 13 and 14 in side elevation withextended telescopic boom on a reduced scale,

FIG. 16 shows a vehicle with an extended three-part telescopic boom in arear view,

FIG. 17 shows the vehicle as in FIG. 16 with retracted telescopic boom,and

FIG. 18 shows a vehicle with a telescopic boom forming an accessibletunnel in a simplified side elevation.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

Telescopic boom 1 according to FIGS. 1 to 6 comprises two box girders 2and 3 guided displaceably in one another whose longitudinal axles forman upwards arched circular arc 4. Lower telescopic boom 2 isswivel-mounted about a horizontal pivot axis 5 in a storage rack 6 whichcan be rotated by a rotary table 7 about vertical axis, so thattelescopic boom 1 can be adjusted about two axes vertical to oneanother. The drive for pivotally adjusting telescopic boom 1 about pivotaxis 5 comprises two pivot cylinders 8 which are linked to both sides oftelescopic boom 1 between lower box girder 2 and storage rack 6. Upperbox girder 3 guided displaceably in lower box girder 2 bears on itsfront end a connecting fork 9 for load uptake. According to FIGS. 4 to 6slideways 10, which are arranged in the region of the rear end of upperbox girder 3 and in the region of the front end of lower box girder 2,are provided to guide upper box girder 3 in inner box girder 2, so thatsaid slideways 10 effectively secure box girder 3 inside box girder 2from tilting, and with adequate play between the cylindrical upper andlower walls 11 and 12 of box girders 2 and 3. So that slideways 10 allowindependent tolerance compensation with respect to the respectivecurvature of walls 11 and 12, said slideways 10 are arranged on pivotmembers 13 which are swivel-mounted on axles 14 parallel to pivot axle5.

As evident from FIGS. 5 and 6, the upper and lower cylindrical walls 12of inner box girder 3 of telescopic boom 1 are elongated laterallybeyond the box profile and with these projecting parts form longitudinaledge frames 15, by means of which box girder 3 is supported on the sidewalls of box girder 2. This lateral extension of the cross-section ofbox girder 3 not only offers advantages relative to the carryingcapacity of box girder 3, but also enables the formation of longitudinalchannels 16 for taking up various supply lines 17 running betweenlongitudinal edge frames 15 outside the box profile on both sides ofinner box girder 2. So that these supply lines can be protected fromoutside influences not only in the retraction zone between box girders 2and 3, but also in the region of the overhang length of box girder 3,longitudinal channels 16 can be closed off outwardly by caps 18.

For mutual displacement of intermeshing box girders 2 and 3 aservo-drive 19 is required. According to FIGS. 3 and 4 said servo-drive19 comprises two rams 20 which on the one hand are each articulated toone of the outer girder ends and on the other hand to a common slider 21swivel-mounted inside box girder 3. Through this arrangement of two rams20 arranged chord-like relative to arc 4 inside box girders 2 and 3achieves the adaptation of telescopic boom 1 to the circular arc shapeis achieved, so that despite the circular arc form simple rams 20 mustnot be dispensed with. Due to the displaceable bearing of slider 21relative to box girder 3 when ram 20 assigned to said box girder 3 issupplied upper box girder 3 is extended relative to lower box girder 2along circular arc 4.

servo-drive 19 may also, however, comprise at least one rack 22 runningalong one box girder, in the embodiment as in FIGS. 7 and 8 along upperbox girder 3, which meshes with a driving pinion 23 arranged in thefront end region of box girder 2 on the storage rack side. According toFIG. 8 two such racks 22 meshing with driving pinions 23 are provided,and in fact in the region of longitudinal channels 16, on both sides ofthe box profile, in such a way that a geared motor 24 is flanged on boxgirder 2 for driving each of driving pinions 23. This configuration ofservo-drive 19 frees the box profile for laying large-diameter supplylines 17. The space of longitudinal channels 16 not utilised by the rackpinions can additionally serve to take up supply lines 17, as indicatedin FIG. 8.

FIGS. 9 to 11 illustrate an advantageous application of a telescopicboom 1 according to the present invention in a vehicle 25 for taking upset-down bins 26. For this purpose telescopic boom 1 is mounted with itsstorage rack 6 via a rotary table 7 in the rear region of vehicle 25 andby way of its connecting fork 9 bears a pivot head 27 which is connectedto a cross-beam 28 of load suspension gear which exhibits respectivelytwo traction mechanisms 29 and 30 for suspended bins 26 on both sides ofcross-beam 28. Whereas of said traction mechanisms 29 and 30 arranged inpairs traction mechanism 29 engages tensilely on cross-beam 28,according to FIG. 12 traction mechanism 30 is fed by way of a deflectionsheave 31 respectively to a hydraulic jack 32, such that tractionmechanisms 30 can be tightened when hydraulic jacks 32 are supplied, inorder to tip suspended bin 26, as is evident from FIG. 10. Due to thecircular arc shape of telescopic boom 1 bin 26 can be set down andpicked up in any orientation within the set-down region of telescopicboom 1 indicated in FIG. 11, by cooperating with pivot head 27 forcross-beam 28, without any additional hoisting equipment having to beprovided for the load suspension gear. It is understood that provisioncan also be made for corresponding height adjustment of the loadsuspension gear. The chassis of vehicle 25 is supported in aconventional manner via stanchions 33 which are attached in the frontregion of the loading surface to retractable and extensible bracingcantilevers 34.

The embodiment according to FIGS. 13 to 15 illustrates a vehicle 25 witha telescopic boom 1 which serves to guide a supply line 17 forready-made concrete, for example. With its lower box girder 2 extendingsubstantially over the length of the vehicle in a storage rack 6 saidtelescopic boom 1 is swivel-mounted about a horizontal pivot axle 5 andcan be rotated by rotary table 7 about a vertical axis. To extend thereach of telescopic boom 1, a cantilever arm 35 is linked to the frontend of upper box girder 3, and in fact by way of a connecting frame 36which can be shifted about a lateral axle 37 running transversely to boxgirder 3 into a laterally pivoted transport position, in whichcantilever arm 35 comes to rest laterally next to telescopic boom 1, asis evident from FIGS. 13 and 14. In the use position, in whichconnecting frame 36 swivelled to in front of the front face of boxgirder 3 is locked with box girder 3, cantilever arm 35 can be pivotedabout a pivot axis 38 parallel to pivot axis 5 of telescopic boom 1 bymeans of a pivoting cylinder pair 39 articulated between connectingframe 36 and cantilever arm 35 as required. These measures enable supplyline 17 to be inserted through lateral openings into spaces which cannototherwise be reached by a straight telescopic boom, as illustrated inFIG. 15, in which different pivot positions of telescopic boom 1 and oflinked cantilever arm 35 are indicated, for ready-made concrete forexample to be supplied via supply line 17 into various upper-level areasof a building 40.

FIGS. 16 and 17 illustrate a telescopic boom 1 for a hoist fitted on avehicle 25, whose load suspension is not illustrated for clarity. Incontrast to previously described telescopic booms telescopic boom 1 iscomposed of three box girders 2, 3 and 41guided displaceably in oneanother. Whereas box girders 2 and 3 can be shifted reciprocally bymeans of a servo-drive as per FIG. 3 or 7, middle box girder 2 ismounted telescopically in both directions in box girder 41, which isswivel-mounted on storage rack 6, where rams 42 are provided for mutualdisplacement, which engage externally on both sides of telescopic boom 1at the upper end of box girder 41 on the storage rack side and at thelower end of middle box girder 2. In the transport position illustratedin FIG. 17 middle box girder 2 projects downwards over box girder 41 onthe storage rack side, so that telescopic boom 1 comes to rest inside aspecified contour 43 of vehicle 25. The full length of three-parttelescopic boom 1 can be utilised in the extended working position as inFIG. 16.

FIG. 18 finally illustrates a telescopic boom 1 which forms a navigableor accessible tunnel with its box girders 2 and 3, in such a way thatbox girder 3 forms a connection 44 at its front end facilitatingtransition to its lateral opening. Such a telescopic boom 1 can aid increating exit hatches for aircraft or emergency and escape routes whichallow people to advantageously and easily reach the ground by way ofopenings which exhibit a corresponding distance from the ground.Similarly to connection 44, at the same time box girder 2 on the storagerack side can be equipped with a sealing cap 45 which facilitatestransition from box girder 2 to the ground when in the unfoldedposition.

It probably does not need to be particularly emphasised that applicationof telescopic booms 1 according to the present invention is not limitedto the illustrated embodiments. Such telescopic booms 1 could also beused beneficially in fire engines, for example. What matters inparticular is that the telescopic boom is moved along a curved path bythe circular-arc arrangement of the box girders in order to improve thereach of these telescopic booms.

1. A telescopic boom mounted for pivoting about a horizontal pivot axison a mounting bracket arranged on a vehicle, which comprises two boxgirders extending in a longitudinal direction in upwardly arched arcs ofa circle and a first one of the box girders being guided in a second oneof the box girders for displacement in the longitudinal direction, theupwardly arched arcs of a circle having a common axis extending parallelto the pivot axis, a servo-drive for displacing the box girders relativeto each other, the first box girder having an end extending into an endof the second box girder and the servo-drive comprising twofluid-operated cylinders for displacing the box girders relative to eachother, each cylinder having one end linked to an outer end of arespective one of the box girders and an opposite end linked to a commonslider mounted displaceably in the end of the first box girder.
 2. Thetelescopic boom of claim 1, wherein the two box girders have endsinterengaging with play, comprising two slideways pivotal about axesextending parallel to the pivot axis, one of the slideways beingsupported at a top of the end of the first box girder end the otherslideway being supported at a bottom of the end of the second boxgirder.
 3. The telescopic boom of claim 1, wherein the first box girderhas an upper and a lower arcuate wall, the upper and lower arcuate wallshaving laterally projecting longitudinal edges guided along the secondbox girder.
 4. The telescopic boom of claim 1, wherein an outer end ofthe first box girder carries a pivotally adjustable cantilever arm. 5.The telescopic boom of claim 4, wherein the cantilever arm isextendible.
 6. A vehicle capable of accommodating a removable bin havinglateral sides, which comprises a telescopic boom mounted for pivotingabout a horizontal pivot axis on a mounting bracket arranged on thevehicle, the telescoping boom comprising two box girders extending in alongitudinal direction in upwardly arched arcs of a circle and a firstone of the box girders being guided in a second one or the box girdersfor displacement in the longitudinal direction, the upwardly arched arcsof a circle having a common axis extending parallel to the pivot axis, apivotal head attached to an outer end of the first box girder, across-beam mounted on the pivotal head, a traction mechanism connectedto the cross-beam, the traction mechanism comprising a pair of tractionelements at respective ends of the cross-beam for gripping the lateralsides of the removable bin, at least one of the traction elements ofeach pair of traction elements being adjustable relative to the othertraction element of said pair and a servo-drive for displacing the boxgirders relative to each other.
 7. The vehicle of claim 6, furthercomprising hydraulic jacks arranged in the cross beam and having endsthereof connected to the adjustable traction elements for adjusting thesame.